PostEaseUse the caption to add what the video cannot show
A caption is a good place for context a viewer might be missing: what led to this moment, why it matters, a detail the video does not make obvious on its own. It does not need to summarize the video. It should add to it.
Ask something specific, if a reply is the goal
A direct, specific question in the caption, one your audience can answer from their own experience, earns more genuine comments than a vague prompt like "thoughts?" A question someone can answer in a few words lowers the effort required to leave a real reply.
Keep it short and let the video lead
A long caption competes with the video for attention in the first couple of seconds, when a viewer is deciding whether to keep watching. A short caption, with any longer context saved for a comment or a follow-up video, tends to work better than a caption that tries to do the video's job.